New high pressure VLE data for the ternary mixture CO2 + n-dodecane (nC(12)) + 3,7-dimethyl-1-octanol (37DM1O) are presented. A static apparatus with online analysis was used to measure phase compositions at 35, 55 and 75 degrees C, and pressures between 68 and 157 bar. In the high-nC(12) region the mixture displayed enhanced solubility, presenting as a pinched two phase band and s-shaped liquid phase curves. Relative solubility, an indicator of fractionation sharpness, increased with 37DM1O content and the 75:25 nC(12):37DM1O mixture cannot be separated using CO2. RK-ASPEN, SR-POLAR, PR-BM and PC-SAFT models were evaluated for their ability to correlate these data. RK-ASPEN and PC-SAFT models provided the best and worst correlation of equilibrium pressures with respective percentage average absolute deviations of 3.1% and 8.5%. RK-ASPEN model was impressive in its ability to capture the co-solubility pinch seen for the 75:25 nC(12):37DM1O mixture and the resultant s-shaped liquid phase complexity.